This invention relates to a plate-type nozzle and a method of using same. More particularly, this invention relates to a plate-type spray nozzle for atomizing liquids and a method of using same.
Atomized liquids are useful in a wide variety of household and industrial applications including, for example, medicinal sprays, spray drying, surface coating, ink jet printing, and liquid fuel dispersion for combustion.
Frequently, liquids are atomized by means of nozzles having bulky, complicated structures which are relatively expensive and time-consuming to make, clean, inspect, re-use and/or replace. On the other hand, nozzles having a plate-like configuration have been used to direct fluid flow are believed to have less complicated and less bulky structures than do non-plate nozzles and are, therefore, often preferred over the bulkier non-plate nozzles.
Plate-type nozzles for directing liquid flow are disclosed, for example, in U.S. Pat. Nos. 4,647,212 (Hankison) and 3,432,357 (Dankese). Other plate-type devices for controlling or directing liquid flow are disclosed, for example, in U.S. Pat. No. 5,014,750 (Winchell et al.); and U.S. Pat. No. 5,176,360 (Winchell et al.).
Although the foregoing references disclose nozzles, the references do not disclose nozzles for atomizing liquids.
Although generally simpler in design than non-plate nozzles, many conventional plate-type nozzles are still too complex and bulky in structure. For example, many conventional plate-type nozzles require the use of multiple plates and/or multiple surfaces of one or more plates. In addition, the plates used in many conventional plate-type nozzles are relatively thick and relatively expensive to make, machine and/or replace.
It would be desirable, therefore, to further simplify the structures of plate-type nozzles used for atomizing liquids. Furthermore, it would be desirable to provide a plate-type nozzle which can atomize a liquid by means of a single surface of a single plate. In addition, it would be desirable to provide a plate-type nozzle for atomizing liquids, wherein the nozzle is composed of one or more relatively thin plates.
In a nozzle designed for the atomization of liquids, mechanical energy is applied to a jet stream of the liquid to be atomized. The mechanical energy causes the jet stream to break up into discrete volumes of the liquid, the discrete volumes exiting the nozzle as drops.
The uniformity of the drop size of the atomized liquid is often important to the usefulness of the liquid in certain applications. For example, atomized liquids used in ink jet printers and fuel injection engines are generally required to contain drops of a substantially uniform size. Drops of a non-uniform size tend to lead to messy printed characters in ink jet printing applications and to decreased control over the combustion process carried out in a fuel injection engine. Therefore, it is continually desirable to provide nozzles capable of forming atomized liquids having drops of a substantially uniform size.
The present invention is based in part on the discovery that oscillation of the jet stream as the stream is being broken up into discrete volumes of liquid in the nozzle results in the formation of substantially uniform drop size in the atomized liquid.
The use of oscillation to form and direct jet streams is disclosed in Humphrey, Eugene F. and Tarumoto, Dave H., Fluidics, Fluid Amplifier Associates, Boston, Mass., 1965, pp.11-16, which is hereby incorporated by reference herein in its entirety. However, this reference does not teach the use of oscillation in a nozzle used to form atomized liquids, that is, a spray nozzle designed to convert a liquid stream into a plurality of drops, particularly a plurality of drops having substantially uniform size. In addition, the use of conventional fluidic oscillators tends to further increase the bulkiness of nozzle systems with which such oscillators are used.
Therefore, it would be further desirable to provide a plate-type nozzle for atomizing liquids, wherein the nozzle itself can provide pressure oscillation and does not require the use of a separate pressure oscillator. In addition, it would be desirable to provide a simplified plate-type nozzle for atomizing liquids wherein the nozzle can be used with a conventional pressure oscillator.
Accordingly, a primary object of this invention is to provide a plate-type liquid-atomizing nozzle which is relatively easy and inexpensive to make, inspect, clean, re-use and/or replace as compared to prior art nozzles.
A further object of this invention is to provide a plate-type nozzle which is capable of producing atomized liquids containing drops of a substantially uniform size.
Another object of this invention is to provide a plate-type nozzle for atomizing a liquid, wherein atomization can be carried out by means of a single plate.
A still further object of this invention is to provide a plate-type nozzle for atomizing a liquid, wherein atomization can be carried out on a single surface of a single plate.
Another object of this invention is to provide a plate-type nozzle for atomizing liquids, wherein the nozzle itself can provide pressure oscillation and does not require the use of a separate pressure oscillator.
A still further object of this invention is to provide a plate-type nozzle for atomizing liquids, wherein the nozzle can be used with a conventional pressure oscillator.
Another object of this invention is to provide a method of atomizing a liquid by means of a plate-type nozzle having the characteristics described in the foregoing objects.
These and other objects which are achieved according to the present invention can be readily discerned from the following description.